Silicon is known for its ready availability and relative ease in processing for fabrication of electronic devices. It has recently been discovered that by electrochemically and chemically etching single-crystal silicon, nanometer structures are formed which convert the silicon into a highly luminescent material. The "quantum wires" that are formed during the etch photoluminesce in the visible region of the electromagnetic spectrum when illuminated as a result of the increase in effective band gap energy.
While the ability to fabricate photoluminescent silicon has clear implications in the development of optical electronics, other applications are also worthy of exploration.
Many industries, including the electronics industry, utilize a variety of organic solvents and gases which present environmental and/or safety hazards. These solvents can be highly volatile and flammable, and can be toxic and/or carcinogenic to those who are exposed to even relatively low levels of the solvent. Thus, in applications where no alternatives exist for these solvents, it is necessary to provide means for determining whether organic solvents are present in areas which should be free of such hazardous chemicals.